Cold cathode glow discharge counting and scaling tubes and circuit arrangements therefor



March 17, 1959 c. H. TOSSWILL EI'AL 2,878,419

com CATHODE GLOW DISCHARGE COUNTING AND SCALING TUBES AND CIRCUITARRANGEMENTS THEREFOR Filed April 14, 1955 SSheets-Sheet I1 VENTORS CHRISTOPHER HALY TOI5VIILL GEORGE FREDERICK wzsron TERENCE EUGENE DAYS AGENT March 7, 1959 c. H. TOSSWILL ETAL 2,878,419

- cow CATHODE GLOW DISCHARGE COUNTING AND SCALING TUBES AND CIRCUIT ARRANGEMENTS THEREFOR Filed April 14, 1955 s Sheets-Sheet z CHFUSTOPHER HALY TO8$WILL GEORGE FREDERICK WE$VON TRENCE EU m; 5

BY %Z7 A G E N T INVENTORS March 17, 1959 c. H. TOSSWILL ETAL 2,878,419

COLD CATHODE GLOW DISCHARGE COUNTING AND SCALING TUBES AND CIRCUIT ARRANGEMENTS THEREFOR Filed April 14, 1955 I 3 Sheets-Sheet 3 TO R5 AGENT United States Patent COLD .CATHODE GLOW DISCHARGE COUNTING AND SCALING TUBES AND CIRCUIT ARRANGE- "MENTS THEREFOR Christopher Haly Tosswill and George Frederick Weston, Reigate, and Terence Eugene Days, Crawley, England, assignors, by mesne assignments, to North American .Philips. Company, Inc., NewYork, N. Y., a corporation of Delaware APPIICafiOIIAPI'II 14, 1955, Serial No. 501,376

8 Claims. (Cl. SIS-84.6)

.This invention 1 relates to devices, more particularly but not exclusively for use in counting circuit-arrange- -ments,. comprising at least one glow-discharge tube hav- Tubes'for use in such devices are known, in which the negative control pulses are delivered to auxiliary catho'desl'ocated between the maincathodes, the auxiliary .cathodes having to fix thedischargefor awhile until the first main discharge path has been deionized. This requires control impulses ofconsiderable energy which .cannot be delivered by such'a tube itself,-so that cascade circuit-arrangements counting with two or more figures require theinteiposition of san amplifier; thus the device becomes more complicated and costly. The present invention has for its object to provide a device to which ,only. pulses of such a value need be supplied as to permit the use of cascade circuit-arrangements without intermediate amplification. In circuit-arrangements com- ;prising only one glowdischarge tube it is also advanttageous to use a pulse of'low energy since in this case less pro-amplification is 1 necessary.

.According to the invention, a device particularly intended for use in counting circuit-arrangements comtprisesatcleastone glow discharge tube having an anode .anda number ofmaincathodes, which determine the 'restupositions of the tube and each of which is associated with a number of auxiliary electrodes. In the glow discharge tube thedischarge' is' transferred'from one rest position to thenext bynegative pulses on the control :electrodes. Auxiliary cathodes are provided near each main cathode in such manner that, during operation the auxiliary cathode associated with a main cathode assumes therpotential of the main cathode, the main and sauxiliarycathodes jointlyiconstituting'arest group. A transfer.groupiislocated between every two such rest groups, and comprises in spatial order: a control electrode, uan extinguishing electrode and a transfer electrode. :The main cathodes 'are connecte'd through resistors to a point of'negative potentialiin the circuit arrangement, the anode is connected through aresistor to the point of maximum positive potential,the extinguishing electrodes are connected through a resistor'to a potential which is more positive thanrthose of the cathodes, andthe-interconnected auxiliary cathodes and transfer electrodes are connected to a potential in between that of the extinguishing 'electrodes and the anode, while all the electrodes, except the control electrodes and the anode, are connected through'capacitors to a point of fixed potential, preferably ground.

ice

With a sufficiently negative control pulse on'thecontrol electrodes, the control electrode nearest the cathode in operation withdraws a given current from the discharge, as a result of which the anode voltage tends to drop. Due to the discharge towards the control electrode the nearby extinguishing electrode is enabled to partake in the discharge in such manner that the discharge to the main cathode becomes extinguished and the "discharge to the control electrode is also of short duration.

Due to transfer of the discharge the potential of the extinguishing electrode rises to such a degree that the nearest transfer cathode, the potential of which has meanwhile dropped, can take over the discharge. The main cathode of the next rest group is located" adjacent said transfer cathode and is at a very low potential so that it takes over-thedischarge. The associated auxiliary cathode, which is connected to the transfer electrode having operated last, then assumes the potential of 'the'main cathode, the discharge remaining on this main cathode.

Dueto the presence of the transfer cathodes, which have the potential of the auxiliary cathodes, the discharge travels only in one direction on applying a negative control pulse.

In order that the invention may be readily carried into effect it will now be described with reference to the accompanying drawings, given by Way of example, in

which:

Fig. 1 is a perspective view of the electrode system for abinary glow discharge tube in accordance with the invention;

Fig. 2 is a plan view of decade counter'tube in ac cordance with the invention;

Fig. 3 is a schematic diagram of a circuit-arrangement comprising a counter tube in accordance with the inventransfer groups comprise control electrodes 7, 12, ex-

tinguishing electrodes 8,13 and transfer electrodes 9, 15.

'Only the cathodes 5, 10 are uncranked, Whereas all'the other electrodes have a cranked end pointed towards'the preceding electrode or main cathode. anode 2 is'carried by a supply conductorfi. The elec- 'trode connections are not shown in the drawing, 'Input A disc-shaped electrodes 7 and 12 are interconnected. Theextinguishing electrodes 8 and 13 are interconnected, and furthermore theauxiliary cathodes 6, 11 and the transfer electrodes 9,15 are connected together. Transfer of the dis- 'chargejfrom one main cathode to the other occurs as follows:

If a discharge isproduced between the anode 2 and cathodeS, the electrode 6 assumes the potential 1of the cathode 5. Since the electrodes 9, 11 and 15are interconnected they assume the same potential as that of the auxiliary cathode 6. In the case of a negative pulse being supplied to the control electrodes '7 and 12 the discharge will partially travel to electrode 7, thus striking the discharge to electrode 8 which is at apotential lower than those of the control electrodes 7 and 12, and the discharge to the cathode "5 extinguishes. Since, upon interruption of the discharge, the potential of the auxiliary cathode 6 drops, that of the transfer electrode 9 also drops so that it takes over the discharge from the extinguishing electrode 8 and transfers it to the'main cathode 10 which is at alowerpotential Upon anext 'which carries fifty electrodes in all.

the diodes D1 and D2.

negative pulse the discharge returns to the main cathode 5. In contradistinction to known counting circuit-arrangements, in which the control electrode has to maintainthe discharge for a while, the control electrode of the present tube need only ignite the next electrode; hence a pulse of much lower energy suffices.

Fig. 2 is a plan view of the electrode system of a decade counter tube which fundamentally corresponds to the binary counter tube shown in Fig. 1. The anode 2 (not shown) is arranged above an insulating disc 105 There are ten rest groups, each comprising a main cathode denoted 100,

110, 120 190, and an auxiliary cathode 101, 111,

121 191. There are also ten transfer groups each comprising a control electrode 102, 112, 122 192, an extinguishing electrode 103, 113, 123 193 and a .transfer electrode 104, 114, 124 194. All the electrodes, except the ten main cathodes, have a cranked end as may be seen from the drawings.

In the circuit-arrangement shown in Fig. 3 all the even numbered main cathodes are interconnected, grounded through a capacitor C and connected through a resistor R to a potential of -50 v. required for transfer of the discharge from a transfer group to a rest group. All the odd numbered main cathodes H 1, 3, 5, 7 are interconnected and, similarly to the even-numbered cathodes, are connected to ground and to 50 v. through elements C R The main cathode numbered H9 is separately inserted in the circuit-arrangement through elements C5 and R5. The anode A is connected through resistor R1 to a voltage of 350 v. The interconnected control electrodes I are connected through a diode D1 to a potential of +50 v., the anode of said diode being connected to the control electrode. The negative input pulses are supplied through a capacitor C1, as indicated symbolically by an arrow and a block voltage. Similarly to the control electrodes, all the auxiliary cathodes G and transfer electrodes F, are connected through a diode D2, to a potential of +50 v. and are grounded through a resistor R6 in parallel with a capacitor C6.

The extinguishing electrodes are grounded through a resistor R2 shunted by a capacitor C2. During operation of the tube, the control electrodes and the auxiliary cathodes with the transfer electrodes may attain a positive potential not exceeding 50 v. due to the presence of The resistors R3, R4 and R5 are so chosen that during the passage of the discharge to the main electrode, these electrodes, like the auxiliary electrodes, are at a potential of approximately 50 v.

During the passage of the discharge to the main cathode Ho and the associated auxiliary cathode Go, a negative pulse on the control electrode I0 produces a discharge to the extinguishing electrode E0. The current flowing to the extinguishing electrode E0 reduces the anode potential so that the discharge to the electrodes Ho and Go is interrupted. The voltage of all the auxiliary cathodes G and the transfer electrodes F drops due to "interruption of the discharge, and upon ignition of the discharge of the extinguishing electrodes their potentials rise. Thus, the discharge of the extinguishing electrode E0 is taken over by the transfer electrode F0, the potentialv of which rises again, with the result that the potential difference between main electrode and transfer electrode F0 rises so that the discharge is taken over by the main electrode H1. Further pulses may cause the discharge to pass to the main electrode H9 and if the output terminal is connected to this electrode, a negative pulse occurs at said output terminal when the discharge of main cathode H9 passes to main cathode Ho, thus completing a cycle. The output pulse may be used for a general indication or for controlling a next tube.

Fig. 4 shows in a vertical voltage scale, which is different for the several curves, and a horizontal time scale, which is the same for all the curves, the variation of the potential of the several electrodes of the tube as shown in Fig. 2. Va represents the potential of the anode, V; indicates the potential of the control electrodes, the idealized pulse being represented as a rectangular block voltage, V represents the potential of the main cathode, the left and right half holding for two succeeding cathodes that is to say cathodes and respectively shown in Fig. 2; V shows the voltage of the auxilitary cathodes and transfer electrodes and V indicates the potential of the extinguishing electrodes. Along the broken lines, which indicate given instants in the time scale, are plotted the number of electrodes, a rising arrow indicating the passage of the discharge to a given electrode and a downwardly directed arrow indicating the extinction of the discharge passing to the electrode concerned.

Fig. 5 shows two cascade-connected counter tubes I and II. The electrodes of these tubes are indexed I and H. The circuit-arrangement of the first tube corresponds to that of the tube shown in Fig. 3 but, for simplification, a number of switch elements have been omitted. Furthermore, the main cathode, indexed O, is no longer connected to the other even numbered main cathode but separately inserted in the circuit through a capacitor C7 and resistor R7. The main cathode H9 of the first tube is connected to the control electrodes I of the second tube through a capacitor C11. A positive voltage of 50 v. is applied to said control electrodes through a rectifier D3. The main cathode H0 of the first tube is connected through a resistor R8 to the extinguishing electrodes E of the second group. Moreover, said extinguishing electrodes are capacitatively grounded through a capacitor C8 and grounded by Way of a rectifier D4 so that the voltage of said electrodes never becomes negative relative to ground. The even numbered main cathodes of the second tube are inserted in the circuit-arrangement with a capacitor C12 and resistor R12, and the odd numbered cathodes with a capacitor C13 and resistor R13. The anode A is connected through a resistor R10 to the positive terminal of the source of potential. If, in the first tube, the discharge travels to the main cathode H9, the capacitors C11 and C5 are charged, and if the discharge thence passes to the cathode H0 the discharge of said capacitors causes a negative pulse at the control electrode I In order to ensure satisfactory operation of the circuit-arrangement, provision is made that the control electrodes I carry current prior to the capacitors C5 and C11 becoming completely discharged. This may result in the passage of the discharge from the first tube H9 to Ho acting as a double pulse on the control electrodes I with the result that the discharge would advance two steps in the second tube. This could be prevented by making the time constant of the switch elements at the interconnected auxiliary and transfer cathodes of the second tube, and also that of the main cathodes, high so that the discharge on an extinguishing electrode is maintained until the capacitors C5 and C11 have become discharged. This, however, might lead to considerable time constants. Instead thereof, use is made of the said circuit-arrangement between the main cathode Ho of the first tube and the extinguishing electrodes of the second tube, with the result that the extinguishing electrodes receive a positive pulse after the negative pulse on the control electrodes. The rectifier D4 prevents the extinguishing electrodes of the second tube being driven negative relatively to ground. The time constant of the circuit R8 and C8 is chosen high, that is to say approximately five times as high as that of the circuit C7 and R7, so that the control electrodes, under the influence of a possible double pulse, yet control the discharge only once.

If, in Figs. 3 and 5, in lieu of the circuit-arrangement shown in Fig. 3, a different circuit-arrangement is used for the control electrodes of the first tube; that is, an arrangement in which the control electrodes are at a considerable negative potential through a high resistor .asrsaig .atolthe control electrode, the sensitivity to small ptllses .imay be'higher, but'then the attainable switching rate. is

Llower.

i iWhat is claimed is:

'1. 'A circuit arrangement comprising a glow discharge tube having an ranode, a plurality of electrode groups reach comprising a main cathode, anauxiliarymathode, a control electrode, an extinguishing electrode and a transfer electrode, said auxiliary cathode defining with said main cathode a rest group and being positioned in operative relation to said main cathode in such a manner that it assumes the potential of said main cathode when said main cathode carries the discharge of said tube, said control electrodes, extinguishing electrodes and transfer electrodes constituting a plurality of transfer electrode groups interposed between adjacent ones of said rest groups for transferring the said discharge from one of said rest groups to another upon the application of a negative pulse to said control electrode, means for interconnecting said transfer electrodes and said auxiliary cathodes, means for applying an input signal to said control electrodes, a first voltage source having a negative polarity terminal and a positive polarity terminal, resistance means for connecting each of said main cathodes to said negative terminal, a second voltage source of substantially greater magnitude than that of said first voltage source having a positive polarity terminal, resistance means for connecting said anode to the positive terminal of said second voltage source, resistance means for connecting said extinguishing electrodes to a point at ground potential, means for connecting said auxiliary cathodes and said transfer electrodes to the positive terminal of said first voltage source, capacitance means for connecting said main cathodes, said extinguishing electrodes, said auxiliary cathodes and said transfer electrodes to a point at ground potential, and means for deriving an output signal from one of said main cathodes.

2. A circuit arrangement as claimed in claim 1, further comprising rectifier means for connecting said control electrodes to the positive terminal of said first voltage source, said means for applying an input signal to said control electrodes including a capacitor connected to said control electrodes.

3. A circuit arrangement as claimed in claim 1, further comprising resistance means having a relatively high resistance value for connecting said control electrodes to a point at negative potential.

4. A circuit arrangement as claimed in claim 1, further comprising resistance means for connecting said auxiliary cathodes and said transfer electrodes to a point at ground potential and rectifier means for connecting said control electrodes to the positive terminal of said first voltage source, said means for connecting said auxiliary cathodes and said transfer electrodes to the positive terminal of said first voltage source comprising a rectifier having an anode connected to each of said auxiliary cathodes and said transfer electrodes and a cathode connected to the positive terminal of said first voltage source.

5. A glow discharge tube having an anode, a plurality of electrode groups each comprising a main cathode, an auxiliary cathode, a control electrode, an extinguishing electrode and a transfer electrode, said auxiliary cathode defining with said main cathode a rest group and being positioned in operative relation to said main cathode in such a manner that it assumes the potential of said main cathode when said main cathode carries the dis charge of said tube, said control electrodes, extinguishing electrodes and transfer electrodes constituting a plurality of transfer electrode groups interposed between adjacent ones of said rest groups for transferring the said discharge from one of said rest groups to another upon the application of a negative pulse to said control electrode, and means for interconnecting said transfer electrodes and said auxiliary cathodes.

6. .A, glow discharge. tube tasclaimedin claim 5,..further Q comprising a support member comprisingelectrically. in-

sulating material, said main cathodes comprising rods transversely supported in said support member, said auxiliary cathodes said control welectrodes,maid-extinguishing electrodes and said transfer-electrodes each comprising a rod having a main stem transversely supported in said support memberand a minor stem appended to an end of said main stem and angularly disposed from said main stem, said last-mentioned rods being so positioned that their minor stems are in predetermined angular relation With each other, the ends of said main cathode rods and the minor stems of said last-mentioned rods being positioned substantially equidistantly from the surface of said support member.

7. A circuit arrangement comprising a pair of glow discharge tubes each having an anode, a plurality of electrode groups each comprising a main cathode, an auxiliary cathode, a control electrode, an extinguishing electrode and a transfer electrode, said auxiliary cathode defining with said main cathode a rest group and being positioned in operative relation to said main cathode in such a manner that it assumes the potential of said main cathode when said main cathode carries the discharge of said tube, said control electrodes, extinguishing electrodes and transfer electrodes constituting a plurality of transfer electrode groups interposed between adjacent ones of said rest groups for transferring the said discharge from one of said rest groups to another upon the application of a negative pulse to said control electrode, means for interconnecting said transfer electrodes and said auxiliary cathodes, means for applying an input signal to the control electrodes of the first of said tubes, a first voltage source having a negative polarity terminal and a positive polarity terminal, resistance means for connecting each of the main cathodes of said tubes to said negative terminal, a second voltage source of substantially greater magnitude than that of said first voltage source having a positive polarity terminal, resistance means for connecting the anode of each of said tubes to the positive terminal of said second voltage source, resistance means for connecting the extinguishing electrodes of said tubes to a point at ground potential, means for connecting the auxiliary cathodes and the transfer electrodes of said tubes to the positive terminal of said first voltage source, capacitance means for connecting said main cathodes, said extinguishing electrodes, said auxiliary cathodes and said transfer electrodes to a point at ground potential, means for coupling one of the main cathodes of the first of said tubes to the control electrodes of the second of said tubes, means for coupling another of the main cathodes of the first of said tubes to the extinguishing electrodes of the second of said tubes comprising a circuit having a relatively long time constant, and means for deriving an output signal from one of the main cathodes of the second of said tubes.

8. A circuit arrangement as claimed in claim 7, wherein said means for coupling one of the main cathodes of the first of said tubes to the control electrodes of the second of said tubes comprises a capacitor and said means for coupling another of the main cathodes of the first of said tubes to the extinguishing electrodes of the second of said tubes comprises a resistor connected between the said other of said main cathodes and each of the extinguishing electrodes of the second of said tubes, a capacitor and a rectifier connected in parallel circuit arrangement with said capacitor, said parallel circuit arrangement being connected in series with said resistor, said resistor and said capacitor having a relatively long time constant and said rectifier being connected With a polarity which prevents the extinguishing electrodes of the second of said tubes from being driven negative relative to said point at ground potential, and further comprising References Cited in the file of this patent UNITED STATES PATENTS 2,598,677 Depp June 3, 1952 8 Skellett JuneflO, 1952 Townsend Ang s, 1952 Gugelberg Nov. 18, 1952 Townsend Apr. 21 ,1953 Depp NovJB, 1953 FOREIGN PATENTS i I Australia J lly 10', 1953 

